Radio channel emulators have been used for many years and are essential tools for signal propagation testing to emulate the radio propagation based on pre-defined environmental conditions. Currently, most channel emulators are designed for low spectral-efficient single-input and single-output (SISO) communication system.
To enhance the performance of the wireless radio transmission, the multi-input and multi-output (MIMO) technology has been developed and is widely applied in various wireless applications. In a MIMO communication system, multiple antennas may be both configured at the transmitter and the receiver to improve the transmission reliability and capacity of the wireless communications there between, thus demonstrating high spectral efficiency.
With multiple antennas included in the MIMO bolt-on device, an appropriate antenna selection scheme that selects a desired antenna for transmission at specific moments is needed. A conventional antenna selection scheme is often implemented by monitoring all antenna's input signal strength, and selecting the antenna corresponding to the strongest input signal as a desired antenna for transmission.
However, in a contended environment, the strongest input signal that an antenna corresponds may be a jamming signal. Accordingly, instead of a desired antenna, the conventional antenna selection scheme may select an antenna corresponding to the strongest jamming signal for transmission, which deteriorates the quality of wireless communications between the receiver and the transmitter. Thus, to sustain the benefit of the MIMO communication system in the presence of jamming signals, an improved antenna selection scheme that avoids impact of jamming signals is desired.
Further, given specific transmission environmental conditions, a channel emulator and a channel emulation method that provide corresponding faded representation of a transmitted signal at the receiver need to be developed, to test the performance of the MIMO bolt-on device flexibly and at a relatively low cost.
The disclosed MIMO bolt-on device, MIMO channel emulator, and MIMO channel emulation method are directed to solving one or more problems set forth above and other problems in the art.